Observations on anthocyanin pigmentation in seedlings and mature plants of Impatiens capensis and its possible role as a determinant of floral form

Abstract

Plants of Impatiens capensis Meerb. were observed in the field for the presence or absence of anthocyanin pigmentation. Seeds were collected at a site where cross-pollination between plants with orange spotted flowers (forma capensis) and plants with orange unspotted flowers (forma immaculata) was highly likely to have occurred. Spotted and unspotted flowers were found to possess a similar array of carotenoids in similar concentrations, but cyanidin glycosides were found only in extracts of spotted flowers. Progeny of spotted flowers were 98% anthocyanin-producing in root tips, roots, hypocotyl, and cotyledons of seedlings (photographs of the unusual development of seedlings are presented). Only a minority of progeny of unspotted flowers were cyanic. One of these cyanic offspring of unspotted flowers was grown to maturity and produced 75% cyanic seedlings when selfed. Under cultural conditions where crossing had been prevented, spotted-flowered plants produced only cyanic seedlings and unspotted-flowered plants produced only acyanic seedlings. All these observations suggest that the presence of anthocyanin pigmentation is a dominant, heritable characteristic of I. capensis forma capensis and its absence a recessive, heritable characteristic of I. capensis forma immaculata and that it is this feature only that distinguishes these two formae.